The morphology and kinetics of the crystal growth front have been poorly explored at the particle level. Here, we experimentally observe the crystal growth front in liquid with single-particle kinetics using colloid systems and reveal a surface layer of polymorphic crystal near the solid-solid transition when the two crystals form a low-energy coherent interface. The thickness of the surface crystal can exceed 50 particles and grows logarithmically with the temperature as approaching the solid-solid transition which follows premelting theory. The liquid-crystal interface grows continuously through random attachments of diffusive particles, while the crystal-crystal interface exhibits a martensitic growth with collective motions. The presence of a surface crystalline layer reduces defect density, which is helpful in crystal fabrication.